Over the last four decades, the density of integrated circuits has increased by a relation known as Moore's law. Stated simply, Moore's law says that the number of transistors on integrated circuits (ICs) doubles approximately every 18 months. Thus, as long as the semiconductor industry can continue to uphold this simple “law,” ICs double in speed and power approximately every 18 months. In large part, this remarkable increase in the speed and power of ICs has ushered in the dawn of today's information age.
Unlike laws of nature, which hold true regardless of mankind's activities, Moore's law only holds true only so long as innovators overcome the technological challenges associated with it. One of the advances that innovators have made in recent decades is to use chemical mechanical polishing (CMP) to planarize layers used to build up ICs, thereby helping to provide more precisely structured device features on the ICs.